def nested_commit_on_success(func):
"""Like commit_on_success, but doesn't commit existing transactions.
This decorator is used to run a function within the scope of a
database transaction, committing the transaction on success and
rolling it back if an exception occurs.
Unlike the standard transaction.commit_on_success decorator, this
version first checks whether a transaction is already active. If so
then it doesn't perform any commits or rollbacks, leaving that up to
whoever is managing the active transaction.
"""
commit_on_success = transaction.commit_on_success(func)
def _nested_commit_on_success(*args, **kwds):
if transaction.is_managed():
return func(*args,**kwds)
else:
return commit_on_success(*args,**kwds)
return transaction.wraps(func)(_nested_commit_on_success)